1. Field of the Invention
This invention relates to a sewing machine, and more particularly, it relates to a dual clamping system having a first clamp and a second clamp which are capable of either separately or simultaneously clamping a first workpiece and a second workpiece, respectively, against a sewing surface in the sewing machine.
2. Description of the Related Art
In the sewing industry, the use of a clamp to clamp or hold workpieces at a sewing station is quite common. It is also common to use a clamp to clamp a label, patch or emblem onto a workpiece, such as a shirt or jacket, so that the label patch or emblem can be sewn thereon. One problem with the sewing machines of the past was that they were only equipped to clamp one workpiece at a time. When manufacturing workpieces having two or more labels sewn thereon, it was often necessary to separately clamp and sew each label onto the workpiece. This usually required a separate clamping and sewing operation for each label.
Another problem was that the operator had to stop sewing the workpiece and change clamps whenever two or more labels of different sizes were to be sewn on the workpiece. For example, if two labels were to be sewn on the workpiece, the operator would clamp and sew the first label with a first clamp. The operator would then change the clamp in the sewing machine and replace it with another clamp that was suitable for clamping the second label. The operator would then clamp and sew the second label. This procedure would be repeated for each different label. The sewing machine usually had to be shut down whenever the operator had to change clamps. This down time resulted in lost production and labor time.
As an alternative approach, an operator would sew a first label on all of the workpieces with a first clamp, and then the operator would change clamps and sew a second label on all of the workpiece with a second clamp. This required that the operator position the workpiece at the sewing station at least two times, thereby resulting in a duplication and repetition of production and labor time.